Improvement in steam-engines



UNITED STATES PATENT OFFICE.

JOSEPH L. LOFVRY, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN STEAM-ENGINES.

Specification forming part of Letters Patent No. 411,327, dated September 20, 1864.

To all whom it may concern:

Be known that I, JOSEPH L. LOWRY, of the city of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Steam Engines; and I hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, forming part of this specification, and to the letters of reference marked thereon, in which Figure 1 represents a front elevation of my improved engine. Fig. 2 is a longitudinal ver tical section of the same. Fig. 3 is a transverse vertical section. Figs. 4: and 5 represent modifications of the valves. Fig. 6 is a cross-section of the condenser.

' All the drawings are lettered, and similar letters denote corresponding parts in the several views.

The invention I have made is intended to apply to that class known as the Cornish pumping-engine. In these engines the steam, as it passes from the boiler, is used for the purpose of lifting the piston, with its immense weight, to the top of the cylinder. The supply of steam is then cut off, and that in the engine condensed, producing a vacuum under the piston, whereby the atmospheric pressure is made to assits the weight attached to the piston to drive or force the water to its place of destination. In my improved engine the steam, after lifting the weighted piston, is allowed to pass into a second cylinder or reservoir, and there held in abeyance until that remaining in the first cylinder is condensed or exhausted. YVhen the vacuum is thus produced, the steam from the reservoir is allowed to act on the other side of the piston and assist the weight in forcing the water.

To enable others skilled in the artto understand and make my invention, 1 will proceed to describe its construction and operation by reference to the accompanying drawings.

I construct my pumping-engine similar in most respects to those already in use; but, in order to work the steam twice in the same cylinder, P, on opening of the throttle-valve G the steam rushes into the side pipe, X, between the piston-valves t 0, and through the ports N, and forces the drivin g-piston, with its ponderous weight B, to the top of the cylinder P, or until the projection R on the weight strikes the tappet T on the valve-rod Y, and lifts the valves sufficiently high to close the ports F at the top of the cylinder, and open (r reverse the ports N at the bottom. This being done, the steam in its endeavor to escape lifts the puppet valve m, and proceeds through the pipe S into the reservoir 0, through the openin g V, communicating therewith, at the same time the steam is passing into a pipe or cylinder A between the piston-valves c d. These valves being of the same size and perfectly balanced, no motion of the valves takes place until the steam begins to act on the under side of the valve 61 by passing through the small pipe 0, which is provided with two openings communicating with the cylinder A, the openings beinggraduated bya choke-valve, g. As the steam acts on the under side of the valve 17, it is lifted very slow, owing to the smallness of opening through which the steam passes, until it is lifted past the larger opening, when its motion is rapidly increased. This drives the upper valve, 0, beyond the exhaust-passages n, which allows the steam to escape into the condenser W. In the meantime the steam that before passed into the reservoir (J, in i s endeavor to rush back closes the puppet-valve m, which holds it in abeyance until the steam that remained under the piston Z in the main cylinder P is either exhausted or condensed. When the piston Z, by reason ofits weight, in connection with the pressure of steam on it, begins to descend, the steam from the reservoir O rushes in above the piston through the openings F around the valve t, driving the piston down by the force of expansion, until the projection R on the weight B strikes the tappet K on the rod Y, and opens the valve t, which permits the expanding steam to pass above the valve 0, and force it down below the openings 11, and enables the steam to escape into the long cylinder A, and press the valve 0 beneath the ports n, allowing the steam to pass in to the condenser W, when the valves are again in position to admit steam under the piston preparatory to repetition of the operation.

The construction of this engine is such that the reservoir (1 is always in communication with the upper end or portion of the cylinder P, regardless of the position of the valves, and can be pliced on top or to one side, (as in this ease,) at the option of the builder. The valves it 0 and n d are of that class known as piston- "alvesj and are forced to Work perfectly true, by reason of the ports over which they slide being a series of vertical openings entirely surrounding each valve. These openings extend into a small circular chamber or passa geway around that portion of the pipe or cylinder in which the valves work, and are connected and communicate with the main cylinder and exhaust or condenser, so as to take or relieve the steam all around the valves as the case may require, thus making the pressure equal on all sides.

The condenser Wconsists of a longiron pipe, L, of large diameter, through which a series I of smaller pipes or tubes, 8, pass. This condenser is so connected to the forcing-pumpp that the water in its passage from the pump p to the basin is forced through these flues or tubes, the steam escaping from the engine into the space between them. The condenser is here represented as standing beside the engine, which is not necessary, as it can be placed longitudinally in a tank, so as to have water flowing all around the outside as well as passing through the tubes, this arrangement would perhaps be better, as it would tend to prevent the tubes from becoming loose by the unequal expansion and contraction of the parts.

Having thus described my invention, what I claim is- 1. The combination herein described for utilizing or reworking the steam or vapor ot' a pumping-engine, after having been used for lifting the piston, with its weight, to the top of the cylinder, or the full length of the upward stroke, by passing it into the other end of the cylinder so as to act on the opposite side of the piston, and assist by the force of' expansion to drive, in connection with the weight the water, through the main pipe to its place of destination.

2. The combination of the valves marked 0 and t and d and 0, for the purpose herein set forth and described.

3. So constructing the condenser of a pumpingengine in connection with the main pipe as that all the water operated on by the pump shall either be forced around or drawn through it, for the purpose of condensing the steam rapidly, however great the quantity.

' JOSEPH L. LOWRY.

Witnesses:

JOHN F. EDMUNDsoN, R. A. CAMERON. 

